Ultrasonic cleaner



FIG. 1 is a perspective view taken from the top, front and right side of an ultrasonic cleaner showing our new design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a rear elevational view thereof, and

FIG. 4 is a bottom plan view thereof.

The electric cord is shown in broken lines in FIG. 4 for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for an ultrasonic cleaner, as shown and described. 